Comets can vary in size, with some being relatively small and others being larger. The size of a comet is typically measured by its nucleus, which is the solid core at the center of the comet. Cometary nuclei can range in size from a few hundred meters to several kilometers in diameter.
If there is a newly discovered or less well-known comet that matches the description you provided, it is recommended to consult with astronomical sources or organizations, such as NASA or the International Astronomical Union (IAU), for the most accurate and up-to-date information regarding its size, periodicity, and potential close approaches to Earth.